Please pick this commit for 4.14 and older stable branches: commit 8e7df2b5b7f245c9bd11064712db5cb69044a362 Author: Ingo Molnar <mingo@xxxxxxxxxx> Date: Mon Nov 13 07:15:41 2017 +0100 timer/debug: Change /proc/timer_list from 0444 to 0400 In older kernel versions this file makes it far too easy to exploit arbitrary-write bugs. It's possible to hide the pointers from unprivileged users by setting the kernel.kptr_restrict sysctl, but that wasn't done by default. (Upstream commits c1eba5bcb643 "timer: Pass timer_list pointer to callbacks unconditionally" and ad67b74d2469 "printk: hash addresses printed with %p" provide more general mitigations, but don't seem to be suitable for stable.) Ben. -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom
